Fans Compressors Turbines for Jet Engines P M
Fans, Compressors & Turbines for Jet Engines P M V Subbarao Professor Mechanical Engineering Department Life Management Systems for A Flying Machine.
Fans & Compressors
Euler Turbo-machine Equation Vwhirl, out Vwhirl, in Applying conservation of angular momentum, the torque, T, must be equal to the time rate of change of angular momentum in a stream tube that flows through the device
Axial Flow Turbo-machines Fan or compressor Rotor Blades The power, P of a fluid Machine
Action & Reaction • If the tangential velocity increases across a moving blade then work is added to the flow ( a fan or a compressor). • If the tangential velocity decreases across a moving blade then work is removed from the flow (a turbine).
Classification of Fans & Compressors Roto-dynamic Compressors Positive Displacement of Compressors Reciprocating Compressors Centrifugal Compressors Hybrid Compressors Axial Compressors Rotory Compressors
Multistage Axial flow fans & Compressors
Schematic representation of a multi stage axial flow compressor
Need for a Stator in multi-stage fan or compressor In general, a rotor also adds kinetic energy along with enthalpy to the fluid. A diffuser known as stator succeed the rotor to convert the excess kinetic energy into enthalpy.
Thermodynamics of An Ideal Axial flow fan/Compressor Stage p 02 = p 03 T 02 = T 03 p 3 V 32/cp V 22/cp p 2 T p 01 T 01 V 12/cp T 1 p 1 s
Euler’s Action behind the increase in Enthalpy of Air
Mean Stream line Kinematics of An Ideal Axial Flow fan/ Compressor Stage Inlet Velocity Triangle Outlet Velocity Triangle
Kinetics of An Axial Flow Fan/Compressor Stage Rate of Change of Momentum: Power Consumed by an Ideal Moving Blade Inlet Velocity Triangle Current Design Practice: Outlet Velocity Triangle
Energy Analysis of An Axial Flow Fan /Compressor Stage Change in Enthalpy of fluid in moving blades: Inlet Velocity Triangle Outlet Velocity Triangle
Level of Compression in A Rotor Power consumed by an ideal rotor : Power absorbed by fluid in a rotor : First law for relative flow through moving blades: Isentropic compression in A Rotor Blade Degree of Reaction of A Stage
Total Effect by an isentropic Stage of a Fan /compressor
Irreversible Adiabatic Stage of an Axial Flow Fan/Compressor p 03 s=p 02 s p 02 p 03 T 02 s T T 03=T 02 Rotor Losses Total Losses T 03 s p 01 T 01 s
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